WEBSTER CITY, Iowa – Pete Buttigieg has been talking a lot lately about “future former Republicans.”

They are potential Iowa caucus voters disenchanted with President Donald Trump who have gone so far as to change their party affiliation and will stand with Democrats on Monday night, and Buttigieg is counting on them to help assemble a winning coalition.

Dozens of them are serving as volunteer leaders in the intense precinct-level organizing across the state and guide his team's effort during the dynamic persuasion that goes on inside the caucuses.

Every candidate seeking a strong finish on Monday night is working feverishly in the closing days to come up with the amalgam of voters to propel their campaign, but the former South Bend, Indiana mayor's approach is among the more novel.

It seemed to work for Veronica Guyader, a 41-year-old estate manager who shouted, “Woo hoo!" from the back of the cramped community center Wednesday as Buttigieg talked about winning over conservative-leaning supporters.

Expanding the caucus electorate has been a key to victory for past caucus winners, but Buttigieg's theory of the case has not been frequently tested.

“If he does well on Monday, it's going to be in part because he galvanized people who don't normally participate in these caucuses,” said David Axelrod, a senior adviser to Barack Obama. “Fallen-away Republicans would certainly fall into that category.”

Buttigieg senior adviser Michael Halle said the campaign has 45 precinct captains who were Republicans as of last year or remain Republicans but plan to change their voter registration to participate in the caucuses, as rules require, for the party-run contest.

“These aren’t just people who are going to show up," Halle said. "These are people who have stepped up and are organizing in their communities.”

Among them are 44-year-old Lisa Fleishman, a general building contractor from a small town south of Des Moines who introduced Buttigieg at Simpson College in Indianola recently.

“A year ago, if you would have told me I’d be doing this, I’d have said you were sadly mistaken,” Fleishman said.

Buttigieg's organizing team in Fleisher's hometown of Carlisle is made up of former Republicans. Likewise, Buttigieg's only organizer in tiny Charlotte, in struggling, rural Clinton County along the Mississippi River to the east, is Saundra Meanor.

Meanor, a 73-year-old dietitian, said she made 80 calls in three days to many of the people she knows in the town of fewer than 400 residents. Although there is no program for targeting Republicans, Meanor follows the campaign's instruction to call people in her personal circles. “So I'm basically reaching out to others I know who are Republicans,” she said.

There's Jeremy Sellars of Decatur County in conservative, rural southern Iowa, and Wright County's Guyader of Wright County, in conservative, rural northern Iowa.

In all, Buttigieg has Republicans serving as precinct captains in 37 of Iowa's 99 counties, with the vast majority in counties Trump won in 2016. Eight of them are in counties that Obama won in 2012 but that Trump turned around four years later.

Buttigieg isn't the only Democratic presidential candidate who has demonstrated appeal to Republicans dissatisfied with Trump. On Wednesday, Massachusetts Sen. Elizabeth Warren's campaign made public a list of 40 Iowa Republicans or Trump voters who were supporting her in the caucuses.

Minnesota Sen. Amy Klobuchar's campaign said some Republicans had volunteered to serve as precinct captains for her campaign. She routinely talks about her Senate success as a Democrat in conservative swaths of Minnesota.

And Republicans like Jenny O'Toole of suburban Cedar Rapids, who was turned off by Trump, have attended events for former Vice President Joe Biden.

Few strategists see an appeal to Republicans as having a downside in a Democratic Party contest. And the one who wins that battle could not only perform well in the caucuses, where expanding the electorate is an asset, but also could improve their chances in subsequent primaries and with swing voters in the general election.

Obama campaign advisers estimate that more than 5% of his support when he won the 2008 Iowa caucuses came from crossover Republicans, and that was during a year when there were competing Republican caucuses.

Buttigieg has not been shy about courting dissatisfied Republicans, notably last year by appearing on a televised town hall meeting on Fox News Channel, a Republican favorite. Buttigieg appeared for another on Sunday from Des Moines.

The approach could help him increase the size of the caucus electorate, always an advantage in a high-turnout contest, but also work to his benefit with caucus participants concerned most with winning in November.

“It's always good to bring in new people,” said Joe Trippi, campaign manager for 2004 Democratic presidential candidate Howard Dean. “And it could help make his case against hyperpartisanship more real to other caucus attenders.”